A conventional automobile floor-type hydraulic jack cannot readily be used on rough or sandy terrain. The problem is that automobile floor-type hydraulic jacks have small-diameter rigid steel wheels that are suitable only for rolling across concrete slab garage floors, but not suitable for rolling across rough terrain; hence, such conventional floor-type hydraulic jacks are not suitable for outdoor use in field conditions. In rough terrain, the small-diameter rigid steel wheels sink into loose or sandy soils and the conventional automobile floor-type hydraulic jack cannot therefore be rolled into position below the undercarriage of a vehicle that requires inspection, maintenance or repairs.